1. Field of the Invention
The present invention relates to transport and storage containers for liquids with a pallet-like underframe, an exchangeable inner container of synthetic material with four side walls, a bottom wall and a top wall, a closeable inlet opening at the top and a lower outlet opening with a draining device, and with an outer casing surrounding the inner container, wherein the outer casing is formed of vertically and horizontally extending grate rods of metal.
2. Description of the Related Art
When liquid containers of this type known from DE 195 11 723 C1 are filled and emptied and when liquids are stirred in this type of containers, for example, for mixing purposes, electric charges may occur at the container surfaces as a result of liquid friction. The principal danger of electrostatic charging is the fact that ignition sources come into contact with explodable mixtures of gases and vapors.
Because the electrostatic charging capability of the inner container of synthetic material, transport and storage containers of the aforementioned type cannot be used in explosion-endangered rooms and cannot be filled with explosive liquids.
In accordance with a possibility for preventing electrostatic charging of containers of synthetic glass fiber described in DE-Z Kunststoffe, Volume 59, 1969, Issue 12, pages 838-842, an electrically conductive lattice is embedded in the wall of the container.
DE 85 19 765.3 U1 discloses flexible transport containers of textile for bulk materials. For avoiding electrostatic charges, the flexible wall material of the containers is provided with a coating which is composed of a metal layer or metal strips and a binding agent with electrically conductive particles embedded in the binding agent.
DE 73 41 620 U1 describes storage tanks for flammable liquids of synthetic class fiber material with an electrically conductive lattice integrated in the cylindrical wall and the floor of the container for preventing electrostatic charging.
DE 32 14 940 A1 discloses foils having properties intended to keep away electrostatic charges. Such foils are suitable for packaging electronic circuit components which must be protected against the harmful influence of an electrostatic charge. The foil originally has a relatively high surface resistance, but is rendered capable of keeping away static charges by imprinting thereon a matrix pattern with the use of electrically conductive printing ink in such a way that on the printed surface are formed at least a first and a second group of conductor paths arranged at a distance from each other, wherein the paths of the groups intersect each other.